Method of acoustic well logging

Abstract

Methods for acoustic logging are described herein. The method includes disposing an acoustic logging tool in a wellbore. The tool includes at least one directional acoustic signal source and at least one acoustic signal receiver. A position of the tool in the wellbore and/or a wellbore shape are determined at each step of acoustic logging before acoustic measurements are taken. A required direction of acoustic signal emission is determined, then an angle of rotation of the logging tool around its axis is computed to provide the determined direction. The acoustic signal source is rotated by the computed angle and acoustic measurements are taken.

1 . A method for acoustic logging, the method comprising:
 disposing an acoustic logging tool in a wellbore, wherein the logging tool is configured to move within the wellbore and the logging tool comprises at least one source configured to emit directional acoustic signals and at least one receiver configured to receive acoustic signals;   determining at least one of (i) a position of the logging tool in the wellbore and (ii) a shape of the wellbore before performing acoustic measurements using the logging tool;   determining a direction for emission of the directional acoustic signals;   calculating an angle of rotation around an axis of the logging tool for the source to provide the direction for emission;   rotating the source by the calculated angle; and   performing acoustic measurements using the calculated angle.   
     
     
         2 . The method of  claim 1  wherein the position of the logging tool in the wellbore is determined on the basis of sensor measurements. 
     
     
         3 . The method of  claim 2  wherein the sensors are ultrasonic sensors. 
     
     
         4 . The method of  claim 2  wherein the sensors are optoelectronic sensors. 
     
     
         5 . The method of  claim 2  wherein the shape of the wellbore is determined on the basis of sensor measurements. 
     
     
         6 . The method of  claim 5  wherein the sensors are ultrasonic sensors. 
     
     
         7 . The method of  claim 5  wherein the sensors are optoelectronic sensors. 
     
     
         8 . The method of  claim 1 , wherein the direction is a required direction.